Short Communication: Preliminary cardiothoracic ratio measurements of south western Nigerian local dog

Abstract

Diagnosis of cardiac diseases is expensive and not available in many Veterinary clinics in Nigeria. Thoracic radiographs are useful in evaluating the heart in all animal species. The canine heart has considerable breed variation than any other organ. A survey of a government and few private clinics in Ibadan revealed lack of use of thoracic radiography in the diagnosis of cardiac problems in dogs. The  Veterinary Teaching Hospital of the University of Ibadan which utilizes thoracic radiographs in diagnosis uses only foreign references of exotic breeds of dogs as there is a dearth of baseline values for local dogs. Six south western Nigerian local dogs comprising two males and four females of about a year old and weighing 14±2.3kg were acquired and stabilised. Dorso-ventral radiographic views of the dogs were taken and their cardio-thoracic measurements were done using a ruler. Cardio-thoracic ratio (CTR) in the dog is usually measured by taking the sum of the
horizontal distances measured from the spine to the most rightward and most  leftward cardiac borders taken as the cardiac diameter and divided by the horizontal width of thorax from inner surfaces of ribs measured at the diaphragmatic apices also known as the thoracic diameter on a dorso-ventral radiograph. The CTR was determined to be 0.47, and is significantly lower than the value of 0.60-0.65 determined for exotic dogs, probably due to the difference in size and management of dogs here in South Western Nigeria. The CTR value is a good indicator together with VHS of changes in cardiac size and is a cheap, noninvasive diagnostic tool.